Sleeping pill that doesn't leave you feeling groggy

People who suffer insomnia could soon be helped with a drug that gets them to sleep - and keeps them that way for up to eight hours.

In a study conducted by Surrey University, people who took the drug EVT 201 were able to get to sleep despite having a box under their beds playing 52 decibels of recorded traffic noise all night.

Those on the drug went to sleep more quickly, stayed asleep longer and woke up less frequently. They felt no bad effects the next morning. In many cases, those who had the drug felt even better.

In pre-clinical studies, the drug showed no tolerance or dependence problems, and no interaction with alcohol.

It is estimated that around half of the adult population have symptoms of insomnia on a regular basis. The causes range from stress or anxiety to too much coffee or alcohol before bed.

It is possible to treat insomnia without resorting to medication. Psychotherapy and relaxation techniques can help, for instance. Some people, however, need sleeping pills.

But while these drugs can relieve the symptoms, they do not tackle the underlying problems, such as grief or stress, and they can have a number of side-effects.

One of the main problems is that users can become tolerant to their effects, resulting in a dependence on the drug which can lead to anxiety and panic attacks. They can also change the pattern of sleep and cause a significant hangover effect the following morning.

EVT 201 works differently from the other drugs on the market. It acts on the GABA receptors in the brain, which are involved in the regulation of alertness and relaxation. We become more relaxed - 'sedated' - as the GABA receptors responses are boosted.

But it is important not to over-stimulate these, because that can affect quality of sleep and result in a hangover effect.

The drug's unique way of working means it only partially boosts the chemical, triggering the release of just enough to get the insomniac to sleep and to keep them that way.

By not boosting the chemical too much, it does not cause meaningful side-effects.

"There is nothing with this mechanism of action on the market or at this stage of development," says Anne Hennecke, spokesman for the manufacturer, Evotec.

The drug is undergoing extensive trials in patients with primary insomnia at a number of centres in America. If all goes well, it is hoped it could be available within four years.

But Professor Jim Horne, director of sleep research at Loughborough University, is sceptical about the new drug.

"I'm afraid the perfect sleeping drug - one that works immediately, allows you to wake the next day feeling invigorated and refreshed, has no side-effects and that you can take night after night without becoming dependent on it - simply does not exist," he says.

"Various claims are made, but all new drugs tend to have some sort of side-effect. The best sleeping tablet is the one you put by the bedside so it is there if you need it - but, with a bit of luck, just sits there gathering dust. But drug companies are not really in favour of that idea."

Meanwhile, a number of other drugs are in development, including two which are designed to trigger a greater release of the sleep-inducing hormone melatonin.

Although the number of drugs is increasing, in most cases they tackle the symptoms rather than the cause - and a solution that addresses the underlying problem is the preferred option for most.

For many insomniacs, cognitive behavioural therapy is proving successful.